tl;dr: Folks want to use ancestry to see where and how it goes. What do they need to know? Is there anything to avoid?
I’m not wild on the idea of submitting DNA swabs for a lot of reasons, the recent issues with genealogy.com’s data being a great example. What of tracing family tree by liniage?
Know that you are not just sharing your own genetic information, but also that of your blood relatives within 2 generations.
Anyone from your grandparents and their offspring can be matched to the DNA you send in. Surpise, your father has an illegitimate child and the will is now in dispute. Oh, looks like DNA of one of your relatives turned up in a criminal investigation so now most are being investigated. That’ll be a fun discussion at the next get together…
There is far more information packed in your genes than most laypeople understand. IMO this whole industry should have been legislated to either force destruction of all data once the report is generated or the consent of all your family members be a prerequisite.